But in the aggregate, the stuff adds up. Just ask anyone who has ever lifted a shovel of snow from a sidewalk or driveway.

Or think back almost seven years to Feb. 6, 2011, when 3 feet of snow caused the collapse of what was the Huron Athletic Club, 319 Huron Ave., Port Huron

Snow has heft.

According to Michael Quaine, senior project engineer at BMJ Engineers and Surveyors Inc. in Port Huron, most structures can handle the usual burden.

"If near freezing, the 10 inches of snow would be equivalent to 1 inch of water," he said in an email. "So every square foot of roof would be carrying approximately 52 pounds per foot.

"If the usual home being 40 by 50 or 2,000 square feet and the roof was a simple peaked roof, the weight of 10 inches of snow would be approximately 5,200 pounds on each side of the roof. Taken as some roofs have support structure (rafters or truss) every 24 inches, the supports would have to bear 208 pounds distributed along the rafter. That’s not too much of a challenge."

He said the issues start as the burden increases.

"The average yearly snowfall in Port Huron is 37 inches," he said in his email. "Melt one-third of that and turn it into ice. It will be approximately 1 1/2 inches of ice, weighing 7.2 pounds per square foot. Adding the rest of the seasonal average as snow will put about 2 feet of snow on the roof weighing an additional 12.8 pounds per square foot.

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Torello Demolition tore down part of the former Huron Athletic Club after part of its roof collapsed under the weight of snow on Feb. 6, 2011(Photo: TIMES HERALD)

"Now that’s 20 pounds per square foot on the roof or a whopping 20,000 pounds each side of our typical house. Can the roof hold an additional 40,000 pounds of weight? Well, the answer is: If it was built to code, it can. Houses are to be designed by a ratio of the ground snow load, which is 28 pounds per square foot in our area and that can sometimes be 70 percent of the ground snow load or about 19.6 pounds per square foot."

Quaine said roofs usually don't have nice even coatings of snow.

"However, the roof also has forces acting on it besides the weight of snow," he said in the email. "Wind can also exert significant forces on the roof. Besides the force of the wind, it can also pile up snow in drifts on parts of the roof significantly higher than the depth I covered above. There have been at least two recent winters where this area received nearly 6 feet of snowfall in a season."

He said although older homes might not have been built to current code, much of the lumber was old growth and denser than modern lumber, and dimensioning was different and often larger than modern lumber. For example, a modern 2 by 4 actually is closer to 1 1/2 inches by 3 1/2 inches.

"In short, the answer to the question of material age cannot be answered without looking a specific structures," he said in the email. "Many were built to quality standards even though there were few public requirements.

"It is useful to understand that homes built today just in compliance with codes are built to the minimum allowable design standards. The effect of age on wood has more to do with the level of exposure it has had to the elements and destructive infestations rather than time."

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Snow covers the rooftops on houses along Sixth Street in Port Huron. More snow is expected tonight and Sunday.(Photo: Brian M. Wells/Times Herald)

According to the experts, removing snow from your roof lessens the chance of ice dams that can cause water from melting snow and ice to back up under the shingles of a roof and leak into a home.

Contact Bob Gross at (810) 989-6263 or rgross@gannett.com. Follow him on Twitter @RobertGross477.